WASHINGTON — American officials said Wednesday that they had obtained credible information that at least some of the 48 Iranianscaptured in Damascus this month by Syrian rebels were members of Iran’s elite Islamic Revolutionary Guards Corps, not the pilgrims described by the government in Tehran.
The new information came as Obama administration officials stepped up accusations of broad Iranian assistance to the embattled government of President Bashar al-Assad of Syria.
Officials would not describe the details that indicated the Iranians held by the rebels of the Free Syrian Army were members of the Revolutionary Guards, citing the delicacy of intelligence-gathering and -sharing efforts in the region, so it was not possible to verify the reports independently. The Iranians were on a bus that they said was on its way to a Shiite shrine when it was seized by the rebels.
“We have received indications that at least some of the passengers on the bus are I.R.G.C., and now in F.S.A. custody,” said one American official, who discussed the information on the condition of anonymity.
Senior Iranian officials have appealed directly to the Assad government for help in gaining the captives’ release. Requests from Iran on other matters have been made to countries on Syria’s border, including Turkey. Potential channels that Iran could use to negotiate with the rebel leaders are, as one government official said, “murky at best.”
Shortly after the Iranians were captured, a video was released by a militant faction, with a rebel leader saying, “They are Iranian thugs who were in Damascus for a field reconnaissance mission.”
During a Pentagon news conference on Tuesday, Defense Secretary Leon E. Panetta and Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, criticized Iran for what they said was its assistance to the Assad government, in particular the training of a pro-government militia. Pentagon officials cautioned that Mr. Panetta and General Dempsey were not speaking specifically of the Iranian captives.
“Iran is playing a larger role in Syria in many ways, not only in terms of the I.R.G.C., but in terms of assistance, training,” Mr. Panetta said. “So we are seeing a growing presence by Iran, and that is of deep concern to us.”
At the Zeinab shrine in Syria, which the Iranians had said they were visiting, regular visitors and merchants cast doubt on Iran’s assertion that the captives were religious pilgrims.
On a recent visit, most sellers at the shrine’s market had fled or closed their shops. The large garages where buses and cars from Iran once parked were quiet, the hotels empty. Abu Hiadar, 50, a Shiite originally from Iraq, said he lived near the shrine and visited every day. “I haven’t seen any Iranian visitors in the past few months,” he said. Several merchants said the decline started a few months after the rebel uprising began last year.